This application claims priority to European Patent Application Serial No. EP 02 022 815, filed Oct. 12, 2002, titled PROCEDURE FOR THE MANUFACTURE OF AN ALL PLASTIC OIL PAN WITH INTEGRATED OIL FILTER, the disclosure of which is incorporated herein by reference in its entirety.
Object of the invention is a procedure for the manufacture of an all plastic oil pan with integrated oil filter for engine and transmission applications.
In accordance with the current state of technology, oil filtration in an engine or automatic transmission takes place through a separate oil filter located outside of the oil pan. For this, oil filters, oil pan gaskets and oil pans are used as separate components. The layout of the oil filter is generally in a manner so that the oil filter is easily accessible and can be easily exchanged during maintenance. This is generally achieved by placing the oil filter outside the surface level of the engine. The size of the oil filter is limited so that the requirement for space can be minimized, which results in a small filter surface which has to be frequency replaced.
To avoid this disadvantage, newer state of technology describes oil filters that are integrated into the oil pan. Regarding this, there are designs that either have the oil filter as a separate plastic component in the oil pan, as well as designs by which a filter component is formed in an area at the bottom of the oil pan. These types of oil pans are for example described in pamphlets DE 197 35 445 A1 and DE 100 08 692 A1 of the registrant.
The manufacture of oil pans with integrated oil filters occurs in accordance with the state of technology that typically uses welding, whereby vibration welding is frequently used. Other laser welding methods are also known to have, however, not yet been successfully implemented in everyday applications.
This type of laser welding for example is described in EP 0 995 535 A2. Regarding this, one filter component consists of plastic material that can be penetrated by a laser beam. The laser beam is run along the laser penetrable plastic material at the point of contact with the other filter component. Through the light absorption by the laser penetrable plastic material heat is generated which results in the joining of both components through this melting process.
The separate plastic components of the oil filter are usually joined through vibration or laser welding. In these procedures the upper filter component is welded to the lower component. The current state of technology includes several types of vibration welding procedures.
U.S. Pat. No. 5,853,577 describes a filter for liquids that consists of an upper and a lower plastic component, whereby these parts are joined through vibration welding. The oil filter is used in engines and transmissions.
U.S. Pat. No. 5,049,274 describes a procedure for the manufacture of an oil filter consisting of an upper and lower component made from plastic. In this procedure the filter material is clamped between an upper and a lower component, and afterwards the upper and lower covers are joined through a vibration welding procedure. The upper filter component includes a pump connection tube. The preferred procedure is linear vibration welding.
The submitted invention pertains to an improvement in the vibration welding procedure of the oil pan with integrated oil filter.
It is a given that during the manufacture of oil filters utmost cleanliness and precision must be used. The oil filter generally has a pump connection tube that extends beyond the surface of the filter component. The assembly to the engine or the transmission is usually performed by installing the oil pan with the integrated filter below the motor or transmission block, whereby the pump tube that extends beyond the filter surface is connected to the engine or transmission block. Afterwards the entire oil pan is assembled to the motor or transmission block by means of the appropriate bushings that are included in the flange of the oil pan.
It is therefore important that the oil pans are manufactured very precisely with tolerance variations held to a minimum during the manufacturing process so that a tension free assembly to the engine or the transmission block is possible. Additionally, deformation, bowing or pressure loading of the plastic components in the assembled state can result in leakage in the welding area which leads to oil leads and in the worst cast to complete filter failure.
Vibration welding is a procedure whereby the components to be welded move against each other. The range of this movement varies depending on the type of vibration welding used. Welding methods that are generally known include, for example, linear welding, orbital welding, circular welding, or ultrasonic welding. A common element of all of these procedures is that the parts to be welded move against each other in defined directions through energy that is created. The resulting warmth results in the melting of the joining flanges so that after cooling the parts are welded together. Since the parts move against each other during the welding process the position of the welded parts after completion of the welding process is not consistent. The variation is in a certain tolerance range depending on the particular vibration welding movements.
Results have shown that parts welded with vibration welding procedures require higher tolerances than parts that are manufactured with a welding process where there is no movement of the parts against each other.
For the perfect function of the engine or the motor it is necessary that the assembly of the oil pan to the engine or transmission block and the assembly of the filter component to the oil pan is so durable that oil leaks and air leakage are avoided. For this it is important to state that the temperature ranges the oil pan is subjected to are considerable and can range from xe2x88x9240xc2x0 C. to 160xc2x0 C., depending on the various geographical regions where the motor or the transmission is used. Added to this is the mechanical load of the oil pan, for example through external occurrences, i.e., stone impact, potholes, etc. The same is true for the oil filter that is integrated into the oil pan that also needs to be sealed tightly to provide problem free function.
The technical assignment for the invention is to modify the vibration welding procedure for the oil pan with integrated filter in a manner so that the finished part has minimum tolerance variability to provide stress free assembly of the part to the engine or transmission block.
The foregoing needs are met, to a great extent, by the present invention, wherein in one respect a method is provided that in some embodiments is utilized to produce an oil pan with integrated filter.
An embodiment of the present invention pertains to a method for manufacturing a plastic oil pan having an integrated oil filter. In this method, a first filter component is assembled. This first filter component includes a filter medium and an oil pan integrated surface section. In addition, the first filter component is placed into a first tool, a second component is placed in a second tool, and the second tool is closed on to the first tool so that a first flange of the first filter component is pressed unto a second flange of the second filter component. Furthermore, the first flange is vibration welded to the second flange. In this manner, the second filter component is fixed upon the oil pan integrated surface section to create a hermetic seal between the second filter component and the oil pan integrated surface section. Moreover, the second tool is separated from the first tool and the oil pan having the integrated oil filter is removed.
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.